The association between pelvic floor muscle function and pelvic girdle pain - A matched case control 3D ultrasound study

There is uncertainty regarding the association between the function of the pelvic floor muscles (PFM) and pelvic girdle pain (PGP), and whether exercises to strengthen the PFM should be recommended for patients with PGP. This one-to-one matched case-control study examined whether there is any difference in voluntary PFM function between women with and without clinically diagnosed PGP. PFM function was assessed by manometry and three-dimensional ultrasound. Images were saved anonymously and analyses were performed offline by one investigator. A special Cox regression model was used to fit a conditional logistic regression procedure for one-to-one matched case-control studies. Forty-nine pairs of women were successfully matched according to age and parity. The study showed no difference in voluntary PFM function measured by palpation, manometry or ultrasound. The size of the levator hiatus area, together with BMI, was significantly associated with PGP. Women with PGP had statistically significantly smaller levator hiatus areas and a tendency for higher vaginal resting pressure compared to the control group. A significantly smaller levator hiatus and a tendency for higher vaginal resting pressure may indicate increased activity of the PFM. Hence, no evidence was found to recommend strengthening exercises for the PFM in patients with PGP. It is important to note that in this study we examined only voluntary contractions and not an automatic response of the PFM to a functional activity.